SQL 无限级分类语句

with tb (ID,Name,ParentID,Sort)
as(
select a.*,convert(varchar,convert(varchar,partid)+'->'+convert(varchar,ID))
from test a where partid=0  --查询所有父节点
UNION ALL
select a.*,convert(varchar,sort+'->'+convert(varchar,a.ID))
from test a inner join tb b on a.partid=b.ID
)
select * from tb order by sort